:root {
  color-scheme: dark;
  --bg: #0b0d10;
  --line: #252b33;
  --text: #f4f7fb;
  --muted: #9aa3ae;
  --accent: #8fb7ff;
  --max: 880px;
}
* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at 82% 4%, rgba(71,117,255,.12), transparent 25rem), var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
}
a { color: inherit; }
.site-header,
.site-footer,
.about-shell {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 28px 0;
}
.brand {
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .14em;
  text-decoration: none;
  text-transform: uppercase;
}
.language-switch {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 11px;
}
.language-switch button {
  padding: 4px 0;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}
.language-switch button[aria-pressed="true"] { color: var(--text); }
.language-switch button:focus-visible,
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.about-intro { padding: 72px 0 48px; border-bottom: 1px solid var(--line); }
.eyebrow { margin: 0 0 18px; color: var(--accent); font-size: 10px; font-weight: 800; letter-spacing: .18em; }
h1 { margin: 0; font-size: clamp(56px, 11vw, 104px); line-height: .92; letter-spacing: -.06em; }
.about-intro > p:not(.eyebrow) { max-width: 720px; margin: 28px 0 0; color: var(--muted); font-size: 17px; line-height: 1.8; }
.about-content { padding: 18px 0 72px; }
.about-content section {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 26px;
  padding: 38px 0;
  border-bottom: 1px solid var(--line);
}
.section-number { margin: 3px 0 0; color: #56606d; font-size: 11px; font-weight: 800; letter-spacing: .12em; }
.about-content h2 { margin: 0 0 14px; font-size: 20px; letter-spacing: -.02em; }
.about-content section div > p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.95; }
.about-content a { color: #c7d8f6; text-underline-offset: 3px; }
.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 0 44px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 11px;
}
.site-footer a { text-decoration: none; }
.site-footer nav { display: flex; gap: 14px; }
[hidden] { display: none !important; }
@media (max-width: 640px) {
  .site-header,.site-footer,.about-shell { width: min(100% - 28px, var(--max)); }
  .about-intro { padding: 48px 0 34px; }
  .about-intro > p:not(.eyebrow) { font-size: 15px; }
  .about-content section { grid-template-columns: 38px minmax(0, 1fr); gap: 14px; padding: 30px 0; }
  .about-content h2 { font-size: 18px; }
  .site-footer { flex-direction: column; }
}